Anton van Leeuwenhoek, using the microscope, was the first to observe bacteria and protozoa.
Answer:
Explanation:
The molecular and cellular mechanisms and processes that explain muscle contraction in striated muscle occur in the myofibril sarcomere. Their understanding depends on the organization's understanding of the structure of the sarcomere. In an imaginary experiment we first assemble an ideal sarcomere.
Remember that the myofibril is a set of cylindrical compartments that are located next to each other, constituting an elongated cylinder. Each of these cylinders is a sarcomere and borders its neighbor on a line or band called, line or band z.
On each side of the z line, thin cylindrical filaments that are actin filaments are inserted. Each actin filament is formed by a double strand of actin molecules that are rolled over each other. In this organization, actin is called actin F.
If you are asking for the complementary DNA sequence, it would be TAACCGAT.
What exactly is the question here? Please answer so i can help you! :)
Answer:
The two main types of DNA organization present in chromosomes are the extended DNI and the condensed DNI
Explanation:
In eukaryotes, the complete chromosome is composed of only one lineal and extremely long DNA molecule. DNA is intimately associated with two types of proteins: <u><em>histones</em></u>, which are structural proteins, and <em>non-histone</em> proteins that mediate different functions of DNA.
DNA associated with histones is called <u><em>chromatin</em></u>. Histones are responsible for packaging DNA molecule, and the fundamental unit of packaging is known as a <em><u>nucleosome</u></em>. As chromatin must be condensed, nucleosomes generate regular structures between themselves forming a <em><u>chromatinic fiber</u></em>, in which DNA is very condensed. A superior level of condensation is the structural <em><u>ringlet-shaped domain</u></em>. At this level, a chromatinic fiber is folded and a protein is responsible for keeping joined the two regions of DNA that form the ringlet. The next condensation level is the rolling of the ringlet-shaped domain composing the <u><em>chromosome</em></u>. The typical chromosome in the metaphase is formed by <u><em>two chromatids</em></u> joined by a centromere. Each chromatid is composed of a sequence of chromatin ringlets domains. In the interphase, <em>before cellular division</em>, chromatin is in a diffuse, lax, uncondensed state, known as extended DNA. When <em>cellular division</em> is about to happen, chromatin begins to condensate. At the beginning of the <em>prophase</em>, DNA is condensed in a well-defined chromosome formed by two sisters chromatids.